Akio Kurose

Catalytic activity of iron and cobalt phthalocyanines wrapped in poly(peptide) for autoxidation of thiol

Abstract The autoxidation of 2-mercaptoethanol was studied by using poly(peptide)-wrapped unsubstituted metal phthalocyanine as a polymer catalyst, where the poly(peptide)s consisted of L-lysine, L-glutamic acid and β-alanine and the metal was iron or cobalt. In spite of the lack of catalytic activity of poly(peptide) or metal phthalocyanine alone, the poly(peptide)-wrapped metal phthalocyanine possessed catalytic activity for the autoxidation of 2-mercaptoethanol. In particular, higher catalytic activity was observed in the polymer catalyst with the higher content of L-lysine residue. The catalytic system was found to obey Michaelis-Menten kinetics with respect to substrate concentration. The rate constant k 2 and the Michaelis-Menten constant K m were determined from a Lineweaver-Burk plot. The overall activation energy E a for the autoxidation was also determined from an Arrhenius plot over the temperature range 10–40°C. Overall, the present polymer catalysts exhibited enzyme-like behavior for the autoxidation of 2-mercaptoethanol.

Flame Retardation of Fe(III)-Poly(vinyl Alcohol) Films

was completely hydrolyzed by alkali solution and purified by dialysis. Metal-PVA complexes were prepared in.,the same way as in our previous papers [2, 5]. Kn aqueous solution of Ti(III), Fe(III), and Zn(II) chloride was added to the PVA solution, and the pH of the mixed solution was adjusted to the desired value with KOH. The molar ratios of total metal ions (TM) to monomeric units of PV A(Tud, T,,~/T&dquo;,_

Synthesis of L-lysine and L-glutamic acid derivatives with long alkyl chains and polycondensation of langmuir-blodgett films

Abstract Two esters of L-lysine and L-glutamic acid containing long alkyl groups were synthesized and their polycondensation in monolayers and multilayers was investigated. The pressure-area isotherms of the ester of L-lysine depend markedly on the time of residence at the air-water interface. The change of FT-IR spectra of the deposited film, which can be lifted as a Z-type film, indicates that polycondensation can occur in the monolayer at 10°C without any treatment. The spectrum of the film cast from chloroform hardly changed with time. These results lead to the conclusion that a regular arrangement of monomer molecules in the monolayer, where the amino and ester carbonyl groups are concentrated, is more suitable for the polycondensation. The ester of L-glutamic acid can also form stable monolayers which can be easily deposited on a hydrophobic plate as a Y-type film by the Blodgett technique. The polycondensation of multilayers under an atmosphere of triethylamine was investigated by IR spectroscopy. ...

Synthesis of Substituted Phenyl Esters of Amino Acids and Polycondensation in Langmuirblodgett Films

Abstract Long-alkyl-chain phenyl esters of β-alanine, glycine, and L-valine were prepared, and their monolayer properties were correlated with their molecular structures. These compounds formed stable monolayers on acidic subphases. In particular, the p-hexadecylphenyl esters of β-alanine and glycine were remarkably stable, and their monolayers could be deposited on calcium fluoride plates as Y-type film by Blodgetts technique. The polycondensation of multilayers under an atmosphere saturated with triethylamine was investigated by changes in the IR spectra. It was determined that the polycondensation proceeded by a first-order reaction mechanism in the initial stage and that the rate in multilayers was faster than that in the bulk crystalline powder. These results suggest that the polycondensation is accelerated by a regular arrangement of the monomer in the multilayers, where the active sites are concentrated and located better for the polycondensation. In the case of the polycondensation in multilayers...

Multinuclear macromolecule metal complexes 2. Preparation and characterization of Prussian blue and its analogs bonded to pofy(vinylamine hydrochloride)

Prussian blue and its analogs bonded to poly(vinylamine hydrochloride) (PVAm · HCl) containing FeII or FeIII and M2+ (M=Fe, Co, Cu) in a 1∶1 molar ratio were obtained by the reaction of [Fe(CN)6]n− (n=3,4) with M2+ ion-PVAm · HCl mixture in aqueous solution. Under a limited polymer concentration (TVAm/TFe over 10), these polymer complexes thus obtained were stable and soluble in water. By casting these solutions, colored films can be produced. The formation of Prussian blue and its analogs bonded to PVAm · HCl was also investigated by the Benesi-Hildebrand method. The molar extinction coefficients of intervalence charge transfer (FeII→FeIII, CoII→FeIII, FeII→CuII) band for MFe(CN)6](n−2)− bound to PVAm · HCl (M=Fe, Co, Cu) were found to be 10,100−9601 · mol−1 · cm−1 at 25 ‡C. The formation constants were found to be in the range of 107 to 1010 M−1. The changes of enthalpy (δH) and entropy (δS) were found to be in the range of −10.4 to −22.5 kJ · mol−1 and 5.7 to 52.9 J · K−1 mol−1 respectively, at 25‡C.

Flammability of Cotton Fabric Treated with Ni(II) Partially Phosphorylated Polyvinyl Alcohol Complexes

In earlier work [I], we reported on the formation and properties of Cu ( II ) partially phosphorylated (30 mol% phosphorus) polyvinyl alcohol complexes (abbreviated as Cu ( II )-phos-PVA ) . We also investigated flame retardation and syntheses of Ni ( II )-phos^PVA [2, 3]. In this work, we have studied flame retardation of cotton fabric treated with Ni ( II )-phos-PVA ( 30 mol% phosphorus) using the limiting oxygen index ( LOI ) method (JIS K 7201) in accordance with Toyorika ON-1. ,

Flame Retardation of Poly(vinyl Alcohol) and Poly(vinyl Chloride) Films Containing Dispersed Metal-Ethylenediamine Complexes

Table I shows that there is not much marked difference in the decrease of cell length and in the increase of cell wall thickness at 1 minute and at 30 minutes of treatment time. Thus it appears that the swelling reaction, which causes the longitudinal shrinkage of the filaments and the increase in cell wall thickness and which is reported to be associated with crimp formation in jute [3, 5], is mostly complete at one minute of treatment time.

Flammability Test of Poly(vinyl Alcohol) Containing Dispersed Metal-Ethylenediamine Complexes

pyrolysis, and graphite structures may be formed [4, 5]. In earlier work [ 1, 2, 3], we reported on the flame retardation ofNi(lI)-partially phosphorylated polyvinyl alcohol complex and Fe(III)-poly(vinyl alcohol) films. In this note, we describe the flammability test of poly(vinyl alcohol) (PVA) containing dispersed metalethylenediamine-(EN) complexes [metal = Fe(III), Zn(II) and Ni(II)]. We used PVA(GL-05), a product of Nippon Synthetic Chemical Industry Co., Ltd. A PVA sample having an average degree of polymerization of 500 was completely hydrolyzed by alkali solution and purified by dialysis. The metal-(EN) complexes and PVA were mixed in aqueous solution. Cotton fabric treated with the metal-(EN)-PVA complexes was studied using flammability test method JIS-1091. After flame, afterglow, char length, and char area of untreated cotton and cotton fabrics treated with metal-(EN)-PVA are summarized in Table I. These experiments clearly indicate the effectiveness of the metal (Fe(III), Zn(II), and Ni(II))-(EN)-PVA complexes for increasing the flame retardation of cotton.